Hydrogenated amorphous carbon-sulfur alloy thin films grown from a CH4 and H2S gas mixture by rf glow discharge

Hydrogenated amorphous carbon-sulfur alloy thin films were grown by capacitively coupled radio frequency glow discharge decomposition of (CH4 + He) and (H2S + He) gas mixtures. Raman and infrared spectroscopies were used to probe the structure of the material. The Raman spectrum has two bands at 1360 and 1550 cm(-1) ascribed to sp(2) clusters. The stretching modes of the C-H bond appear as a broad band in the 2700 to 3200 cm(-1) region. In addition, both IR and Raman spectra have a pronounced band at 670 cm(-1), which is attributed to a C-S vibrational mode. The energy gap, (E(04)) similar to 1.6 eV, is determined by photothermal deflection spectroscopy. The photoluminescence spectrum reveals a single band centered at about 1.3 eV. Gas evolution spectra are analyzed and interpreted in terms of structural features.